﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class Class1
    {
        public double mianji(double r) {
            double s = 3.14 * (r * r);
            return s;
        }
        public double mianji(double a, double b) {
            double s = a * b;
            return s;
        }
        public double zhouchang(double r)
        {
            double c = 3.14 * 2 * r;
            return c;
        }
        public double zhouchang(double a, double b)
        {
            double c = (a + b)*2;
            return c;
        }
        public int jisuan(int a, int b) {
            int x = a + b;
            return x;
        }
        public double jisuan(double a, double b)
        {
            double x = a + b;
            return x;
        }
        public string jisuan(string a, string b)
        {
          return  a + b;
           
        }
        public int jisuan(int a)
        {
            int sum = 0;
            for (int i = 1; i <=a; i++)
            {
                sum = sum + i;
                
            }
            return sum;
        }
    }
}
